English
Maharashtra State BoardSSC (English Medium) 10th Standard

Write scientific reason. A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor. - Science and Technology 1

Advertisements
Advertisements

Question

Write scientific reason.

A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.

Explain
Short/Brief Note
Advertisements

Solution

  1. The electric heater-cooker works on the principle of heating effect of electric current.
  2. Alloys (such as nichrome) as compared to metals have higher resistivity.
  3. Unlike metals they can be heated to higher temperature.
    Hence, a coil made up of alloy nichrome is used in the electric heater-cooker as a resistor.
shaalaa.com
  Is there an error in this question or solution?
Chapter 4: Effects of electric current - Write scientific reasons

APPEARS IN

SCERT Maharashtra Science and Technology 1 [English] 10 Standard SSC
Chapter 4 Effects of electric current
Write scientific reasons | Q 5

RELATED QUESTIONS

Why does the cord of an electric heater not glow while the heating element does?


Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.


Why is the tungsten used almost exclusively for filament of electric lamps?


When current is switched ‘on’ in a room heater, it ______.


What is nichrome? State its one use.


Write down the formula for the heat produced when a current I is passed through a resistor R for time t.


Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.


 How much heat will an instrument of 12 W produce in one minute if it is connected to the heat produced by it?  


Which of the following characteristic is not suitable for a fuse wire?

(a) thin and short
(b) thick and short
(c) low melting point
(d) higher resistance than rest of wiring


Two exactly similar heating resistances are connected (i) in series, and (ii) in parallel, in two different circuits, one by one. If the same current is passed through both the combinations, is more heat obtained per minute when they are connected in series or when they are connected in parallel? Give reason for your answer.


Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate:

  1. the total current taken from the supply
  2. the resistance of each heater and
  3. the energy supplied in kWh to the three heaters in 5 hours.

Why does tungsten metal used to make solenoid type coil in an electric bulb?


Give scientific reason :
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster, etc., an alloy such as Nichrome is used, not pure metals.


Name any six domestic appliances based on the heating effect of electric current.


Answer the following question:
what is the heating effect of the electric current? state any four applications of it?


Write the mathematical expression for Joule’s law of heating.


Find the odd one out and give its explanation.


What is a short circuit?


What is overloading?


Write two devices based on the heating effect of electric current.


Live wire and neutral wires have a 220 V potential difference.


When does overloading occur?


Define fuse.


An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220 V. What is the current in each case?


Assertion: Bending of wire decreases the resistance of the electric wire.

Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.


B1, B2 and B3 are three identical bulbs connected as shown in Figure. When all the three bulbs glow, a current of 3A is recorded by the ammeter A.

  1.  What happens to the glow of the other two bulbs when the bulb B1 gets fused?
  2. What happens to the reading of A1, A2, A3 and A when the bulb B2 gets fused?
  3. How much power is dissipated in the circuit when all the three bulbs glow together?

 


(a) Observe the diagram given below and state whether the bulb will glow or not when we switch on K.

(b) Is it safe to handle the bulb when the switch is OFF?

(c) Give a reason for your answer in (b).


An electric cell produces electricity from the ______ ______ in it.


Unscramble the following words:

SFEU


Your teacher has shown you the following activity.


Activity: Teacher has wound a long insulated piece of wire around an iron nail in the form of a coil. Free ends of the wire are connected to a cell through a switch as shown in the following figure. The current is switched on and some pins are placed near the ends of the nail.

Write down any three questions that come to your mind about this activity.


An MCB can be used instead of a fuse in an electrical circuit.


What are the factors affecting heating effect of electric current?


Name the effect of the current responsible for the glow of the bulb in an electrical circuit.


Name a few appliances which work on the basis of the heating effect of current.


Explain why fuse wire is always connected in a series arrangement.


In the electric equipment producing heat like iron, electric heater, boiler, toaster etc., an alloy such as nichrome is used, not pure metals.


State the law that explains the heating effect of current with respect to the measurable properties in an electrical circuit.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×